Equipment information

Pilot Radio and Tube Corporation Super WASP K-110 Receiver
Pilot Radio and Tube Corporation
Model Super WASP K-110
Category: Radio, Communication
Group Receiver
Description Double Duty Receiver for long and short waves
                                    HEN the original Wasp receiver was being designed, the
question arose as to whether wc thonld merely add an audio
amplifier or at once attempt a stage of radio-frequency
amplification. Even a very brief analysis showed that it
would be wise to defer the R.F. stage until several
questions could be answered in better form than that
represented by the short-wav« tuners on the market. The Wasp
therefore appeared with an audio amplifier, and it was
exceedingly well received by short-wave broadcast listeners.

Having found the Wasp to be entirely satisfactory in the
field as well as in the laboratory, we were encouraged to
proceed with the original purpose of nsing a stage of tuned
R.F. This has been done in the Super-Wasp, to the final form
of which the entire Pilot staff has contributed in one
manner or another. A considerable portion of the work was
done simultaneously in New York, by John Geloso and Robert
Hertzberg, and at the writer's West Hartford, Conn,,
so that independent information might be used to disclose
any of those errors which happen too often when all work
together at one place and become victims of an opinion.

The Super-Wasp as it now stands is unquestionably the best
allround short-wave receiver ever offered the listener. Its
points of superiority are as follows: (1) Increased
sensitivity and selectivity made possible by the TUNED
screen-grid R.F. stage. (2) Universal wavelength range.
Tones from 14 to 500 meters. An excellent broadcast receiver
as well as tbe finest of all short-wave sets. (3) Absolutely
no "hand capacity" effects. (4) Completely shielded. (5)
Easily assembled and wired from kit of parts. (6)
Inexpensive. And last, bat most important, (7) Ability to
bring in short-wave broadcasting stations better than all
previous short-wive receiver!.

Builda Super-Wasp and experience tbe greatest of all radio
thrills—hearing foreign broadcasting stations. The editor of
RADIO DESIGN, while testing a Soper-Wasp for a few minutes
after dinner and then again before going to bed (location:
New York), beard stations in Chelmsford, England; Manitoba,
Canada; and Costa Rica, Central America! These were
broadcasting voice and music, NOT CODE.

Beginning with the matter of shielding, one had at once the
question of the material to be used and the thickness
required. Aluminum has some evident advantages in that it
does sot tarnish readily, may be formed easily and is light.
It was therefore used and a light gauge made possible by
placing tbe R.F. shield and the detector shield at opposite
ends of the set. The baseplate or “snb-panel" of tbe set was
made of much heavier sheet aluminum so as to provide a
zero-potential plane which would not be upset by currents
flowing in it. For the same reason also the panel was made
of heavier material.

There is not space here to discuss the reasons which led to
the particular location of the wiring, the use of a ground
at each socket, the series feed of the 222 plate supply
through the tuned detector-feed circuit, or the rather
unusual circuit arrangement inside the cans. We can say only
that the R.F, amplification obtained has been so adjusted
that it produces a very handsome improvement in performance
(as compared with the Wasp) while at the same time assuring
a gratifying freedom from "crankiness". Since the set is to
be used with all sorts of antennas this obviously means that
the R.F. gain cannot be pushed to extremes.

For this so apology is offered. On the contrary, I wish to
assert that any materially greater gain would be worse than
useless since the “useful selectivity'1' of the set would be
ruined thereby, besides creating operating difficulties in
the way of uncontrolled oscillation when the set is worked
under improper conditions. The practical set for sale in kit
form ir the on« which works when correctly assembled—not the
one which works if everything is exactly and critically


In the broadcast region the Super-Wasp can be thought of as
comparing very nicely indeed with other four and five-tube
sets. Obviously one must not expect the same selectivity
from two tuned circuits as from three or four, nor will a
single 222 develop the same gain as a number of the same. It
is therefore not pretended that seven-tube performance has
been obtained. None the less, both the sensitivity and the
selectivity are such as to permit good use of the set to be
made in tbe normal broadcast band whenever the short waves
are behaving badly. Similarly, when the normal receiver is
struck by a "dead evening", the Super-Wasp need bat be
shifted to the short waves.

Tbe first model Super-Wasp had been provided with R.F, coils
carrying primaries, also providing for condenser feed from
the antenna to the top (grid) end of the tuned circuit. This
was tbr same arrangement that had been used in the original
Wasp receiver. It was found that tbe condenser feed was not
well suited for use in the broadcast region of 200-500
meters for the reason that satisfactory coupling could not
be obtained unless the feed condenser was enlarged
materially. When this was done the condenser was of a
capacity which tuned the antenna as a series system and
produced a condition of two-frequency response—a wholly
inoperative condition.

These manuals are available for the above equipment:

Manual Type User Manual Pilot-7207-Manual-Page-1-Picture
Pages 12
Size 580.12 Kbytes (594038 Bytes)
Language english
Quality Scanned document, reading partly badly, partly not readable.
Upload date
MD5 65edbedf2ab3ff6ad4e03be58d616fb4
Downloads 88 since 27 September 2015

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